Build your sauna the correct way.  Install this special heat reflecting perforated foil vapor barrier directly onto your studs after thoroughly insulating your sauna.  Insulate all walls and ceiling with unfaced fiberglass batts then install this foil vapor barrier, and finally install your interior wood.  It's well worth doing right.  This roll is 256 square feet, enough for a sauna that measures 6' x 7' and has a 7' ceiling.  If you need a larger amount contact us directly at 800-809-9111 weekdays 10-6 and Saturdays 10-3.